Multiwavelength search for and studies of active galaxies

Abstract

We present surveys and related studies of active galaxies carried out at the NAS RA V.Ambartsumian Byurakan Astrophysical Observatory (BAO). This has been one of the main research subjects at BAO for many years since the mid-1950s, when Viktor Ambartsumian suggested the hypothesis of the activity of the galactic nuclei. A number of surveys of and searches for active galactic nuclei (AGN) and other active galaxies were accomplished during the 1960s-1980s. Since the mid-1990s, our research group carried out new surveys and studies of active galaxies based on the First Byurakan Survey (FBS or Markarian Survey) and then a number of others. Here we also present the recent results of studies on active galaxies (both AGN and starbursts) by the Extragalactic Group of the Byurakan Astrophysical Observatory (BAO) Research Department "Astronomical Surveys". These studies are characterized by a multiwave- length approach to the statistical analysis of a large amount of data obtained in different wavelengths, from X-ray to radio. A fine classification scheme for active galaxies has also been suggested. Results on HRC/BHRC sample objects (optical identifications of ROSAT X-ray sources), studies of Markarian galaxies in UV and multiwavelength SEDs, abundance and star formation determinations in Mrk galaxies from SDSS spectra, revised optical classification of LINERs, study and classification of SDSS spectra for Byurakan-IRAS galaxies, summary of observations and study of Byurakan-IRAS galaxies (BIG objects), discovery of new bright ULIRGs from the IRAS PSC/FSC Combined Catalogue and their spectral classification, radio variable sources at 1400 MHz and their optical variability, classification of BZCAT objects having uncertain types (BZU objects), and optical variability of blazars are presented.